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Patented May 9,. "899. F. W. AYER.

DIGESTER.

(Application filed Jan. 9, 1699.)

(No Model.)

UN TED STATES PATENT OFFICE.

FRED \V. AYER, OF BANGOR, MAINE, ASSIGNOR TO THE EASTERN MANU- FACTURINGCOMPANY, OF SAME PLACE. I I

DIGESTER.

SPECIFICATION forming part of Letters Patent No. 624,608, dated May 9,1899.

Application filed January 9, 1899. Serial No. 701,609. No model.)

To all whom it may concern.- point in sufficient quantity to seriouslyattack Be it known that I, FRED \V. AYER, of Banthe shell, but will befree to become distribgor, county of Penobscot, and State of Maine, utedto such an extent as not to seriously inhave invented an Improvement inDigesters, jure the shell.

of which the following description, in connec- Figure 1 is an elevation,partly in section, 55

tion with the accompanying drawings, is a of a digester embodying theinvention; Fig. specification, likeletters on the d rawingsrep- 2, asectional detail thereof; and Figs. 3 and resenting like parts. 4,respectively, perspective views of the two The present invention relatesto a digester forms of bricks which are preferably used in of the kindcommonly employed for making lining the retort. 6o wood-pulp, and ismainly embodied in a novel The digester embodying the inventioncomconstruction and arrangement of the lining prises the metallic shell0., provided at one for the digester-retort, whereby the metallic endwith an inlet 0?, the construction of the body or shell is protected romthe action of shell and inlet being substantially the same acids andgases which are used in reducing as that heretofore employed indigesters of the wood to pulp. this class. The said shell in accordancewith In accordance with the invention the methis inventionis providedwith a lining b, tallic body of the digester is first provided soarranged as to afford a space or series of with a lining of brick laidthereon, the said intercommnnicating spaces (indicated at b 20 liningbeing so arranged that each brick is between the lining proper and thesurface of supported directly by the metal shell, being the shell, intowhich space a fluid cementiin contact therewith, while a space is leftbe- 'tions material capable of subsequent hartween the said lining andthe surface of the dening may be poured, the mass of material metallicshell, there being a projecting supbeing shown at c, Fig. 2. To affordthe said 2 5 port for each brick of lesser area than that of space,there are a series of projecting supthe body of the brick itself. Thesesupports ports b interposed between the surface of the are preferablyformed integral with the bricks shell and the surface of the liningproper, themselves and project from the surface therethe said projectingsupports being herein of in the form of tongues of lesser sectionalshown as formed integral with the lining- 30' area than the surface areaof the brick. By bricks b and being smaller in area than the thisconstruction a space or a series of insurfacesofsaidbricks, so thatwhenthe bricks tercommunicating spaces is afiorded between are laid withtheir edges adjacent to each the surface of the brick lining and theinner other to form a continuous lining spaces are surface of themetallic shell, and the said afforded, as shown in Fig. 1, between the35 space is. shown as filled with a cementitious projecting portions bthus forming the inmaterial in fluid state capable of hardeningtercommunicating spaces between the inner after the space is thoroughlyfilled. The comsurface of, the lining and the shell, as above pletelining then consists of brick and cement, stated. It will be seen thatby this construethe brick, however, being not only embedded tion thebrick lining is directly supported 40 in the cement, but also positivelysupported throughout upon the inner surface of the shell, by themetallic shell, and it is found that a although such a space or seriesof spaces is lining constructed in this way is unaffected afiorded thatwhen the cementitious material by the expansion and contraction of theshell, is poured in it will permeate from one end to so that it does notcrack when the digester is the other of the digester, the result beingthat 45 heated in use. It is not, however, essential when thecementitious material hardens the to the invention that the said spaceshould be said digester is lined throughout with acomfilled with cement,it being practicable to bined brick and cement lining. While itisdeleave the space empty, in which case it is obsirable to fill thesaidspace with cement, as devious that such acid as may leak through thescribed, the said space may, as stated, be left 50 lining will not beconcentrated at any one open, in which event it will obviate the tend-I00 ency of the acid to be concentrated near a leak and will also affordmeans for occasional tests to ascertain whether or no the brick liningis tight, such tests being readily made by circulating a liquid throughthe said space, or,

if desired, steam, water, or other diluting or neutralizing fluid may becontinuously circulated through said space While the digester is in use,so as to cleanse the shell of any acid which may leak through thelining. For this purpose the space, if left open, may be provided withinlets and outlets 6 as shown, it

being obviously immaterial whether the inlets and outlets are present ornot when the cementitious material is employed. I do not,

however, herein claim this specific construction and arrangement, sinceit forms the subject of another application, filed by me July 15, 1898,Serial No. 686,015.

To assist in the circulation of the acid or other fluid which isadmitted to the digester to reduce the wood, the shell is shown asprovided with a supplemental inner lining d, provided with a passage dhaving inlets and outlets d communicating with the interior of theretort, so that the fiuid admitted to said retort can circulate freelythrough said passage from one end of the retort to the other andpermeate the material therein from both ends, thus hastening the actionand rendering it more uniform throughout the mass. To

obtain the said inner lining and at the same 'time to supplement thelining proper and assist in preventing leakage therethrough, bricks arepreferably used, said bricks being formed, as best shown in Fig. 4,withtwo surface portions 61 of equal area connected together by bodyportions 01 of lesser area, so that when the said bricks are laid withtheir edges adjacent,as shown, there are two continuous lining-surfacesand a passage between them around the body portion (1 to afford meansfor circulating the fluid. The inlets and outlets to the said passagemay be afforded by making holes in the inner surfaces of some of thebricks, as best shown in Fig. 4, the said holes being indicated by thereference-letter 01 These inner lining-bricks may be arranged to breakjoints with the outer liningbricks, so as to obviate as far as possiblethe tendency of the acid to leak through the lining, although thecementitious material, if used, will tend to correct defects in thebrick portion of the lining, while if this material is not used suchacid as may leak through can be washed away, as hereinbefore described,before itcan materially injure the metallic shell, and in any event willnot collect and remain where the leak occurs.

While the construction herein shown and described is simple andefficient, it is not intended to limit theinvention to such specificconstruction, since it may obviously be departed from without departingfrom the invention.

I claim 1. A retort comprising a metallic shell and a lining thereforcomposed of. bricks, each of which has a portion of its surface directlysupported on a portion of the shell, the portion of surfacein contactwith the shell being smaller than the main surface, wherebyintercommunicating spaces are afforded between the bricks and the shell;and a filling of cementitious material in said spaces, substantially asdescribed.

2. A retort comprising a metallic shell and a lining therefor composedof bricks having projecting portions of lesser area than that of themain surface of the bricks and being laid with their main surfacesadjacent to each other and their projecting portions in contact with theinner surface of the metal shell; and a filling of cementitious materialin the space between said bricks and said shell, substantially asdescribed.

3. A digester comprising a metallic shell and a lining of acid-resistingmaterial, a space between said shell and said lining separated from theinterior of the digester-chamber,

. and a circulating-passage within the said lining in communication withthe said chamber for the better distribution of the agents admitted tothe chamber to act on the material therein substantially as described.

,4. The herein-described lining for a digester, comprising a series ofbricks each havinga pro- 'j ecting portion of smaller area than that ofits face portion, the said face portions being laid side by side toafford a continuous lining-surface, and a series of other bricks havingtwo face portions connected together by a body portion of lesserdiameter than that of said face portions, the said bricks being laidwith their face portions adjacent to each other and one set of faceportions in contact with the other bricks, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

FRED XV. AYER.

WVitnesse's:

H. M. BURR, CHARLES H. BARTLETT.

